For the drive of bowl-mill roller crushers with a grinding bowl rotating about a vertical axis use is made of heavy-duty transmissions which convert the rotational movement provided by a horizontally arranged driving motor into a vertical, slow rotation. Driving motors frequently used in this case are electric motors, the rotational speed of which has to be stepped down, for example in a ratio of 40:1.
Since drives of this type have to produce a high transmission of power at low rotational speeds, a bevel gear stage already bringing about a first stepping-down of the rotational speed is used for the deflection of the driving spindle. The rotational speed is then stepped down further in the vertical direction by a reduction stage, for example in the form of an epicyclic transmission or planetary transmission.
A heavy-duty transmission for the drive of grinding bowls situated vertically is known, for example, from CH 694 244. In this case, a bevel gear stage having a horizontal drive shaft is connected vertically to a multi-stage epicyclic transmission which finally drives the grinding bowl. The epicyclic transmission here is designed as a multistage planetary transmission with power division, in which power accumulated in the ring wheel toothing of the ring wheel body of the planetary transmission is output.
The object of the present invention is to find a heavy-duty transmission of this type which permits simple installation while having a compact construction.
This object is achieved according to the invention by a heavy-duty transmission of the invention as disclosed herein.
Further embodiments according to the invention emerge from the features of the invention described below.
A heavy-duty transmission is proposed for the drive of bowl-mill roller crushers with a bevel gear stage having a horizontal drive shaft and vertical output shaft and a multi-stage epicyclic transmission arrangement which is connected to the output shaft via a sun pinion and can be connected to the grinding bowl of the bowl-mill roller crusher via an output flange. According to the invention, in a first plane, planet wheels which engage in a meshing manner in the sun pinion are arranged on a planet carrier, wherein the planet carrier is connected to the output flange. Furthermore, further planet wheels, the rotational axles of which are connected to the transmission housing, are arranged in a second plane and engage firstly in a ring wheel connected to the planet carrier and engage secondly in a sun pinion of an intermediate wheel which has a further ring wheel which engages in a meshing manner from the outside in the planet wheels of the first plane.
A very compact transmission with power division is therefore proposed, in which the power firstly is transmitted directly into the output flange by the axles of the planet wheels via the planet carrier and secondly is transmitted into the output flange by a further planet stage via a ring wheel connected to the planet carrier. In addition, the mechanical construction of the transmission advantageously permits a simple installation and construction of the transmission in the transmission housing, since the individual components of the transmission can simply be inserted from above onto the location provided for them. Retrospective upkeep, repair and maintenance work to individual components of the transmission are therefore also facilitated, since, under some circumstances, it is not necessary for the entire epicyclic transmission to be removed and inserted in one piece. Furthermore, the compact construction of the transmission according to the invention means that the individual parts have a small size, as a result of which they can be produced more cost-effectively and are also easier to handle.
Three planet wheels, for example, are arranged in the first plane. The planet wheels are preferably arranged at a regular distance from one another, i.e. at an angle of 120° with respect to the longitudinal axis from one another.
At least three planet wheels, for example, are arranged in the second plane. The planet wheels are also preferably arranged here at a regular distance from one another, i.e. at an angle of 120° with respect to the longitudinal axis from one another.
The first plane, for example, is arranged above the second plane, said planes preferably being arranged one directly above the other. The power splitting and the arrangement of at least three planet wheels per stage result in a very compact construction of the transmission according to the invention. The power splitting results in a lower amount of power to be transmitted in the second stage, and therefore the latter can have smaller dimensions.
The planet carrier is designed, for example, as a ring wheel within which all of the further gearwheels of the epicyclic transmission arrangement are arranged. Firstly, the epicyclic transmission arrangement is therefore covered by the planet carrier as the radially outermost boundary and, secondly, the planet carrier can therefore simply be raised upwards out of the epicyclic transmission arrangement.
An exemplary embodiment of the present invention is explained in more detail below with reference to a figure.